C
While it's true, no one person is perfect, it should be our goal to eliminate intentional / premeditated sin, those things we do which we know we should not do. As we grow in obedience and self control then we are far less likely to give in to sinful behavior when we are caught by suprise and instinct kicks in for example: you are far less likely to say a four letter word when you accidentally stub your toe! *lol*)